Pronzini's take is tautalogy, and
close to a non-sequiter. He makes the rules and he gets to
classify whatever comes up. He apparently has a definition of
hard boiled tucked away in his head, and any counter example
anyone wants to offer he will either shrug off by saying it
is "imitative" or a "tribute" or that it isn't hard boiled at
all. Such proclamations are nice for getting folks excited,
but once you poke at them, there's not much of substance to
discuss.
If Bill thinks it's dead, that must
mean he doesn't intend to write any more of it. That's
okay.